Sight glass



FIG. 1 is a perspective view of a sight glass showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines and all unshaded areas depict portions of the sight glass that form no part of the claim.

The dot dash dot broken lines depict the boundaries of the claim and form no part thereof. 

CLAIM The ornamental design for a sight glass, as shown and described. 